This invention relates generally to the field of communications and more particularly to a system and method of trafficking telecommunication signals having different formats.
Telecommunication networks in North America generally support the Synchronous Optical Network (xe2x80x9cSONETxe2x80x9d) format. Telecommunication networks in various other parts of the world, such as Europe, typically support the Synchronous Digital Hierarchy (xe2x80x9cSDHxe2x80x9d) format. When transmitting signals internationally it is typically necessary to traffic the signals through both SONET and SDH networks. As used throughout this document, the terms xe2x80x9ctrafficxe2x80x9d or xe2x80x9ctraffickingxe2x80x9d refer generally to the transmission, reception, switching, mapping, performance monitoring and various other functions relating to management of telecommunication signals.
Transitioning from a SONET network to an SDH network generally requires terminating the SONET-based synchronous path and associated overhead portions of the SONET-based signal, extracting a desired asynchronous payload, remapping the payload into an SDH-based signal, and reconstructing the synchronous path and associated overhead portions according to SDH standards. Transitioning from an SDH network to a SONET network typically involves similar steps of path termination, embedded signal extraction, signal remapping, and reconstruction of synchronous path and associated overhead according to SONET standards.
There are disadvantages associated with having to terminate the synchronous path and overhead portions associated with these signals when transitioning between networks supporting different formats. Terminating the synchronous path and associated overhead portion increases the cost of the equipment by introducing additional ports necessary to handle the lower-level embedded signals after path termination. Terminating synchronous path and associated overhead also increases the probability of signal integrity loss during the transition from one format to the other. Each time the synchronous path and associated overhead is terminated and reconstructed, there is an additional potential for introducing error.
In accordance with the present invention, a system and method for trafficking telecommunication signals having different formats is provided that substantially eliminate or reduce disadvantages or problems associated with previously developed systems and methods. In particular, the present invention facilitates trafficking telecommunication signals having a first format over a network supporting a second format, without terminating the synchronous path or associated overhead portions of each signal.
In one embodiment of the present invention, a method of trafficking telecommunication signals having various formats comprises providing, at a first network element, a synchronous payload envelope having a first format, the synchronous payload envelope comprising a synchronous path and associated overhead portion and a payload portion, mapping the synchronous payload envelope into a transport signal having a second format without terminating the synchronous path or associated overhead portions of the synchronous payload envelope, and transmitting the transport signal to a second network element over a network supporting the second format.
Technical advantages of the present invention include the provision of a method and apparatus for trafficking telecommunication signals having a first format over a network supporting a second format without terminating the synchronous path or associated overhead portions of each signal. Cross connecting signals having different formats without terminating the synchronous path or associated overhead portions of the signals provides an advantage of facilitating inexpensive switching across SONET and SDH networks while preserving the ability to monitor the performance of the signals being switched. Eliminating the need to terminate synchronous path and associated overhead portions of the signal saves equipment cost by eliminating the need for ports to terminate embedded signals. Avoiding termination of the synchronous path and associated overhead portion also aids to ensure signal integrity by leaving the synchronous path and associated overhead portion intact. Other technical advantages are readily apparent to one of skill in the art from the attached figures, description, and claims.